This invention relates to a continuous process for the manufacture of dialkyl disulfides by reacting an alkyl alcohol with hydrogen sulfide over a solid, particulate catalyst, in one reactor zone and then passing the reactor effluent into a second reaction zone, where it is reacted as a vapor with elemental molten sulfur in the presence of the same or different solid, particulate catalyst. More particularly, it relates to a two-reactor process for the continuous manufacture of a dialkyl disulfide from a C.sub.1 -C.sub.12 alkyl alcohol, hydrogen sulfide, and sulfur, in the presence of solid particulate catalysts.
The process reactions are represented by the following equations: EQU catalyst(1)2ROH+2H.sub.2 S.fwdarw.2RSH+2H.sub.2 O(reactor 1) EQU catalyst(2)2RSH+S.fwdarw.RSSR+H.sub.2 S(reactor 2) EQU 2ROH+H.sub.2 S+S.fwdarw.RSSR+2H.sub.2 O(overall process) (3)
When R is methyl, for example, the process can be utilized to prepare dimethyl disulfide (DMDS) from methanol, hydrogen sulfide, and elemental sulfur, according to equation (3) above. DMDS is a well known article of commerce, being used as a sulfiding agent for the pre-treatment and post-regenerative treatment of hydro-desulfurization catalysts in petroleum refining, as a down-hole sulfur solvent for oil wells, and as a chemical intermediate in the manufacture of agricultural compounds in lieu of methyl mercaptan.